Signal devices for filters



Aug. 7, 1956 M. MUGGLl ET AL 2,757,801

SIGNAL DEVICES FOR FILTERS Filed May 5, 1953 2a 1 2: M: 5 k 1 .30 L l 1 7 9 a E i s 1 1 i n Y, l 27 I; 23 1 5 I 17 11 Mi 3.? 24 16 52 M JINVENTObR S.

am 11 aEwai zi zgqylz ATTD R N EYE United States Patent SIGNAL DEVICES FOR FILTERS Meinrad Muggli and Ewald Muggli, Glen Ullin, N. Dak.

Application May 5, 1953, Serial No. 353,196

2 Claims. (Cl. 210-164) This invention relates to filters used primarily in gasoline supply lines of motor vehicles in which sediment of the gasoline is collected in the lower part of a cupshaped body, and in particular a filter having a cupshaped body with an inlet connection in the upper end, an outlet connection in the lower end and a drain connection also in the lower end and spaced from the outlet connection, and a pressure switch threaded in the drain connection and connected by a suitable circuit to a warning light.

The purpose of this invention is to provide means for warning an operator of a motor vehicle when the filter of the gasoline line contains sediment that restricts 0r prevents conventional operation thereof.

Fuel lines of internal combustion and other engines are provided with means for removing foreign matter and particularly particles of material suspended therein and in the usual operation of a vehicle very little attention is paid to a filter provided for this purpose. For this reason it is possible for sediment to accumulate in a conventional filter and at times the accumulation of sediment in the filter prevents usual operation or efiicient filtering of material passing therethrough. With this thought in mind this invention contemplates a pressure switch mounted in a fuel filter and means for restricting the flow of fuel into the filter, whereby with an accumulation of sediment in the filter, pressure builds up in the filter sulficiently to actuate the pressure switch whereby a circuit to a warning light is completed.

The object of this invention is, therefore, to provide a warning device that is adapted to be mounted on a fuel filter of an internal combustion or other engine to show when the filter ceases to function properly.

Another object of the invention is to provide a warning device for a fuel filter to indicate that the filter is inoperative, in which the device may be installed on filters now in use.

A further object of the invention is to provide a fuel filter having means incorporated therein for indicating that the filter is inoperative in which the means is of simple and economical construction.

With these and other objects and advantages in view the invention embodies a bushing having a relatively small orifice therein adapted to be threaded into the inlet connection of a filter, and a pressure switch having a warning light connected in a circuit extended therefrom adapted to be threaded into a drain connection of a filter.

Other features and advantages of the invention will appear from the following description taken in connection with the drawing, which shows a side elevation of a fuel filter with parts broken away, showing the inlet and drain connections and with elements threaded in the inlet and drain connections shown in section.

Referring now to the drawing wherein like reference characters denote corresponding parts the filter indicating device of this invention includes a cup-shaped casing having a cylindrical section 10, an insulating lining 11 positioned in the casing, a washer 12 positioned in the lining, a diaphragm 13, formed of rubber or other suitable material also positioned in the casing, a thin copper disc 14 positioned below the diaphragm, a pin 15 slidably mounted in an opening 16 in the washer 12, contact pins 17 and 18, a warning light 19, and a bushing 20 having an orifice 21 in the end thereof.

The casing 10 is provided with a threaded nipple 22 that extends from a frusto-conical shaped section 23 at one end and the opposite end is crimped inwardly providing an annular flange 24 that secures the lining 11 in position in the casing. The lining may be formed of rubber, glass or other suitable insulating material and the pins 17 and 18 may be fused or otherwise secured therein.

The pressure switch is mounted in the drain connection 48 of a filter 27. The pressure switch comprises a contact bar 25 that is secured to the end of the pin 18 and a loop 26 on the opposite end that is positioned to engage the end of the pin 17 when the pressure in the filter 27 increases due to the clogging thereof.

In the normal operation of the device wherein the pressure in the filter is comparatively low, the spring 28 positioned below the contact 25 urges the pin through the opening 16 with the diaphragm 13 and disc 14 bowed sufiiciently to permit the loop 26 of the contact 25 to be spaced from the end of the pin 17.

The filter 27 is provided with an inlet connection 29 into which the bushing 20 is threaded and the bushing is connected to the inlet or supply tube 30 of the filter. The filter is also provided with an outlet connection 31 and an outlet tube 32 is connected to the connection 31 with a coupling 33.

The pin 18 is connected by a wire 34 to a ground 35 and the pin 17 is connected by a wire 36 to one terminal of the light 19, the opposite terminal of which is connected by a wire 37 to a battery 38 that is connected to a ground 39 by a wire 40.

With the parts arranged in this manner, conventional pressure, under which a filter operates permits the diaphragm 13 and disc 14 to bulge upwardly with the contact 25 separated from the pin 17 and when sediment closes the outlet 32 whereby pressure builds up in the filter, the diaphragm 13 and disc 14 are moved to the position shown in the drawing whereby a circuit is completed to the light.

As an illustration, with 30 pounds of pressure ahead of the metered orifice 21 approximately 10 pounds pressure would exist in the filter, however, should the sediment obstruct the outlet passage of the filter the pressure therein may build up to 25 pounds, at which pressure the diaphragm 13 and disc 14 would be moved to the fiat positions as shown in the drawing whereby the circuit would be completed to the warning light, as described.

It will be understood that modifications, within the scope of the appended claims, may be made in the design and arrangement of the parts without departing from the spirit of the invention.

What is claimed is:

1. In a warning device for a fuel filter, having a filter casing provided with an inlet and two outlets, one of said outlets constituting a drain connection which is positioned at the lower end of the filter casing and said drain connection being normally closed by a signal de vice, said signal device comprising a signal device casing having a threaded nipple positioned with said nipple threaded in the drain connection of the filter casing, spaced contact pins positioned in the signal device casing, a contact arm also positioned in the signal device casing and mounted on one of the said pins, and means actuated by a pressure rise created in the filter casing as the result of an increase in the differential pressure between the inlet and the other outlet of the filter casing for urging the contact arm into engagement with another of said pins.

2. In a warning device as in claim 1, wherein the means actuated by said pressure rise comprises a diaphragm.

1,960,662 Como et a1. May 29, 1934 &

Bressler Apr. 2, 1935 Eisler Aug. 31, 1943 Schelly May 9, 1944 Braun Nov. 13, 1945 Greer Mar. 7, 1950 Marvel May 12, 1953 Ehrman Feb. 16, 1954 

